The use of magnetic bearings in rotary machines such as centrifugal gas compressors is increasing. Magnetic bearings work on the principle of electromagnetic suspension. The use of electromagnetic suspension reduces or eliminates friction losses in centrifugal gas compressors.
Magnetic bearings in rotary machines are generally arranged with multiple windings or electric coils surrounding a shaft formed from a ferromagnetic material. Some magnetic bearings use a ferromagnetic lamination on the shaft when the shaft is not formed from a ferromagnetic material. The windings in a radial magnetic bearing radially surround the shaft and produce a magnetic field that tends to attract the rotor shaft. The attractive forces of the windings may be controlled by varying the current in each winding.
E.P. Patent Ser. No. 2,448,088, to K. Weeber discloses a rotor shaft assembly that includes a rotor landing sleeve shrunk-fit onto each end of the rotor shaft. The landing sleeve engages an inner race of a roller-element backup bearing in the event of a rotor landing.
The present disclosure is directed toward overcoming one or more of the problems discovered by the inventors.